Firefly pump-metering system

ABSTRACT

A pumping and metering dual piston system for simultaneously injecting controlled amounts of sample and reactants into a reaction chamber and an enzyme into an adjacent injection chamber. A rotary shaft is actuated to communicate the injection chamber with the reaction chamber and to actuate a mechanism for forcing the enzyme from the injection chamber to the reaction chamber. Additionally, the shaft supports and operatively rotates detector apparatus from a magnetic and light radiation shielded position to a position for monitoring the reaction chamber constituents.

Unite States 1' Inventors George M. Low

Acting Administrator of the National Aeronautics and SpaceAdministration with respect to an invention of;

Chris J. lPlakas, Champaign, llll.

Appl. No. 15,022

Filed Feb. 27, 1970 Patented Oct. 26, 19711 lFliREFLY PUMP-METERINGSYSTEM 6 Claims, 1 Drawing Fig.

U.S. Cl 23/259, 23/253 R, 73/4256, 141/23, 195/127, 222/71, 222/135,222/309 Int. Cl G01n1/14, B67d 5/16 lField oli Search 23/259 [56]References Cited UNITED STATES PATENTS 3,012,863 12/1961 Feichtmeir23/259 X 3,192,968 7/1965 Baruch et al.... 23/259 X 3,192,969 7/1965Baruch et 211.... 23/259 X 3,193,359 7/1965 Baruch etalm. 23/2593,184,122 5/1965 Nerenberg 23/259 X 3,525,592 8/1970 Buckley 23/259 XPrimary Examiner-Morris O. Wolk Assistant Examiner-R. E. SerwinAt!0rneysR. F. Kempf, Earl Levy and 'G. T. McCoy ABSTRACT: A pumping andmetering dual piston system for simultaneously injecting controlledamounts of sample and reactants into a reaction chamber and an enzymeinto an adjacent injection chamber. A rotary shaft is actuated tocommunicate the injection chamber with the reaction chamber and toactuate a mechanism for forcing the enzyme from the injection chamber tothe reaction chamber. Additionally, the shaft supports and operativelyrotates detector apparatus from a magnetic and light radiation shieldedposition to a position for monitoring the reaction chamber constituents.

FIREFLY PUMP-METERING SYSTEM The invention described herein was made inthe performance of work under a NASA contract and is subject to theprovisions of section 305 of the National Aeronautics and Space Act of1958, Public Law 85-568 (72 Stat. 435; 42 USC 2457).

The present invention relates to a pumping and metering system forlaboratory sample analysis, and, more particularly, to an instrument forautomatically mixing a sample with reactants and for injectingcontrolled amount of the same into a reaction chamber. Simultaneously,an enzyme or other reagent is metered into an adjacent injectionchamber. A rotatable shaft is then actuated to operatively connect thereaction and injection chambers and to actuate a mechanism for forcingthe reagent from the injection chamber into the reaction chamber. Theshaft further is actuated to operatively position detector apparatus inregistration with the reaction chamber for monitoring the constituentstherein.

BACKGROUND OF THE PRIOR ART A typical pumping and metering system of theprior art is described in U.S. Pat. No. 3,l93,358 wherein a reciprocablepiston divides a surrounding housing into two reacting chambers. Anadjusting screw is utilized to limit piston travel enabling thedispensing of a measured portion of a mixed sample and reagent. Adisadvantage of such construction resides in a requirement for separatesample and reagent mixing chambers and the absence of an automaticcontrol for simultaneously mixing the sample and reagent and positioningde tector apparatus for monitoring the mixed constituents.

BRIEF SUMMARY OF THE INVENTION Apparatus according to the inventionprovides a storage unit for separately containing a sample, reactantsand an enzyme or other reagent. A solenoid valve is activated to mix thesample and reactants and inject the same into a reaction chamber.Simultaneously the solenoid valve permits injection of the reagent intoan injection chamber. Volume of the injection chamber is controlled by areciprocating piston, the travel of which is purposely preadjusted.Volume of the reaction chamber is purposely metered by controlled travelof a second floating piston. As the injection and reaction chambersreceive the reagent and sample, the two pistons will be caused to stopin abutting engagement with each other thereby metering controlledamounts of reagent and sample within the respective chambers. Arotatable shaft is then automatically actuated to operativelycommunicate the injection chamber with the reaction chamber. Further,actuation of the rotatable shaft releases a spring-loaded mechanism forslidably forcing the first piston to compress the reagent and force thesame from the injection chamber into the reaction chamber. Additionally,rotation of the shaft rotatably positions a photomultiplier or otherdetector apparatus into registration with the reaction chamber in orderto monitor the constituents therein.

OBJECTS OF THE INVENTION An object of the present invention is toprovide apparatus for pumping and metering controlled amounts of sample,reactants and reagents into adjacent controlled volume chambers, and forautomatically mixing the sample and reagent within one of the chambers,and operatively positioning a detector apparatus for monitoring theconstituents of said chamber.

Another object of the present invention is to provide apparatus forautomatically pumping and metering controlled amounts of sample to areaction chamber and controlled amounts of reactant to an injectionchamber, and further for simultaneously automatically mixing the sampleand the reactant and positioning detector apparatus which monitors themixed constituents.

A further object of the invention is to provide a reactant injectionchamber defined by a first controlled travel piston, a sample-receivingreaction chamber, the volume of which is determined by a floating secondpiston engageably stopped on said first piston, an automatic mechanismfor reciprocating said first piston in order to transfer the reagentfrom the injection chamber to the reaction chamber.

Another object of the present invention is to provide a reaction chamberand injection chamber each defined by a reciprocating piston, one of thepistons metering a controlled amount of sample injected into thereaction chamber and the other piston both metering a controlled amountof reagent supplied to the injection chamber and pumping the reagentinto the reaction chamber.

Other objects and many attendant advantages of the present inventionwill become obvious upon perusal of the following detailed descriptiontaken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a schematic in elevationand partially in section illustrating a preferred embodiment of thepumping and metering system according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With more particularreference to the drawing, there is generally illustrated in the FIGUREat It) a storage and distribution unit comprising a housing 12 providedwith three cylindrical vertically oriented storage cavities l4, l6 and18. The storage cavity M is provided with :a cover plate 20 havingattached thereto an inverted depending retaining collar 22 havingattached thereto one end of a compression coil spring 24 extendingaxially vertically within the storage cavity 14. The other end of thecoil spring 24 is secured to a reciprocab ing piston 26 provided with acircumferentially surrounding ring seal 28. Similarly, the cavities l6and 18 are provided with cover plates and structure similar to thatdescribed in conjunction with the cavity 14. However, such structurewill not be described in detail for clarity. The bottom portions ofcavities M and 16 are connected by a reduced diameter passageway 30having a plug valve or other suitable valve 32 interposed therein. Thebottoms of cavities l6 and 18 are provided with vertically orientedoutlet passageways 34 and 36, respectively. The passageways 34 and 36extend through and communicate with a laterally extending, enlargeddiameter bore 38. Slidably reciprocable within the bore 38 is anelongated armature 40 of a solenoid 42 mounted on a lateral surface ofthe housing 12. The armature 40, shown in its retracted position, isprovided with longitudinally spaced reduced diameter portions 44 and 46which portions, will register in line with the passageways 34 and 36,respectively, when the armature 40 is in its extended position.Accordingly, in such extended position, the armature 40 acts as anautomatically actuated double distribution valve. The passageways 34 and36 are connected to distribution conduits 48 and 50, respectively. Theconduit 48 operatively supplies a four-outlet distribution manifoldindicated schematically at 52. Similarly, the conduit 50 supplies adistribution manifold 54 similar in construction to the manifold 52.

In the FIGURE, there is illustrated generally at 56 a fragmentaryschematic of an injection unit 56 provided at its lowermost portion withan aluminum chamber block 58, only a portion of which is illustrated inthe fragmentary view. The chamber block 58 is provided with a verticallyextending bore 60 within which is received an elongated rotary shaft 62.The top portion of the chamber block 58 is provided with an enlargeddiameter recess 64 laterally offset from the bore 60. The recess 64lopens into a generally reduced diameter bore 66 coaxial with the recess64 extending vertically parallel to the rotary shaft 62. In practice,the rotary shaft 62 is disposed centrally of the chamber block 58 andfour laterally offset bores 66 are provided. However, for clarity, onlyone of such bores will be described in detail hereinafter.

lOlOU'I 0049 The recess 64 receives therein a transparent glass window68 which forms a sealing cover plate for the bore 66. Alaterallyextending intake passageway 70 extends through the chamberblock 58 into the bore 66 immediately adjacent to and under the bottomsurface of the window 68. The passageway 70 is provided with a shutoffvalve 72 to which is connected one outlet 74 from the distributionmanifold 52. In similar fashion, an inlet passageway 76 is providedthrough the chamber block 58 adjacent the bottom wall of the bore 66.

The passageway 76 communicates with a shutoff valve 78 to which isoperatively connected one of the outlet conduits 80 of the distributionmanifold 54.

Axially aligned with the bore 66 is an inverted recess 82 provided inthe chamber block 58. A generally centrally located opening connects therecess 82 with the bottom portion of the bore 66 and has mounted thereina generally annular sealing ring 84 which surroundingly and slidablyreceives a reciprocating piston shaft 86. At one end of the piston shaft86 is secured a generally cylindrical piston 88 disposed within thebottom portion of the bore 66. The piston 88 carries a circumferentiallysurrounding sealing ring 90 which sealably isolates the bottom portionof the bore 66 from its remainder thereof to define a reagent injectionchamber 92. Accordingly, the injection chamber 92 is supplied throughthe conduit 76, the shutoff valve 78 and the outlet conduit 80 of thedistribution manifold 54. In the remaining portion of the bore 66 isdisposed a floating piston 94 carrying a surrounding annular sealingring 96. The floating piston 94 carries a depending adjusting screw 98having a flat head provided purposely to stop against the piston 88 in amanner to be hereinafter described in detail. Accordingly, the piston 94sealably isolates the top portion of the bore 66 and defines thereby asample reaction chamber 100 which is supplied by the conduit 70, theshutoff valve 72 and the outlet conduit 74 of the distribution manifold52. It should be noted, that the remaining not shown bores 66 areprovided with similar structure and are supplied in similar fashion bythe remaining outlet conduits from the manifolds 52 and 54. A detaileddescription of the same is omitted for purposes of clarity.

With more particular reference yet to the FIGURE, the reciprocatingpiston shaft 86 is slidably extended through the inverted recess 82 andis provided with a surrounding concentric injection compression spring102 retained initially in compression against the bottom wall of therecess 82 by an impinging injection spring retainer 104 slidablyreceived in the recess 82 but initially restrained against movement by aball latch 106 partially protruding into the recess 82 and engaged in agroove 108 provided circumferentially of the injection spring retainer104. The reciprocating piston shaft 86 is slidably received centrally ofthe injection spring retainer 104. The end portion of the reciprocatingpiston shaft 86 is threadably provided thereover with a volumeadjustment nut 110 initially in spaced relationship from the injectionspring retainer 104. Initially, the ball latch 106 is retained inregistration with the injection spring retainer 104 by a ball releasemechanism illustrated schematically at 112. The ball release mechanism112 is rigidly secured to and is adapted for rotation by the rotaryshaft 62 to position a recess 113 as hereinafter described. A motor 114is operatively connected to the rotary shaft 62. In its generallycentral portion the rotary shaft 62 is provided with a reduced diameterconduit groove 116 which extends generally parallel to the central axisof the shaft. The reagent injection chamber 92 is provided with anoutlet passageway 118 and the sample reaction chamber 100 is providedwith a similar reduced diameter passageway 120. Each of the passageways118 and 120 communicate with the groove conduit 116 of the rotary shaft62. It should be understood, however, that such communication occursonly upon rotation of the rotary shaft to be hereinafter described indetail. Accordingly, the initial position of the groove conduit and therecess is illustrated in phantom line at 116' and 1 13' so thatinitially no communication between the reagent injection chamber 92 andthe sample reaction chamber 100 can occur.

The remaining end of the rotary shaft 62 is operatively connected with aphotomultiplier or other suitable detector mounted within a magneticcasing 122. For added support, the casing 122 may be carried by amounting tray 124.

Casing 122 may be carried by a mounting tray 124 secured to the topportion of the chamber block 58. For further protection, the casing 122may be contained within an inverted light shielding housing 126 alsosecured to the top portion of the chamber block 58 by any well-knownfabrication techniques.

In operation, a quantity of sample to be tested is deposited within thecavity 16 of the storage and distribution unit 10. Additionally, aquantity of another substance, such as ATP extracts, is deposited withinthe cavity 14. Also, a reagent or a quantity of any enzyme may bedeposited in the cavity 18. Each cavity is then covered with itsappropriate cover plate 20. The depending spring 24 of each cover platewill be compressed due to the quantity of substance within each cavity.Accordingly, each piston 28 will exert pressure upon the quantity ofsubstance within each storage cavity. Subsequently, the plug valve 32 isopened to permit communication between the cavities 14 and 16, forexample, to mix the sample with the ATP extracts. Simultaneously, thesolenoid 42 is actuated, thereby extending its armature 40 and aligningthe reduced diameter portions 44 and 46 thereof with the outlet conduits34 and 36. Ad a result of the solenoid actuation, the mixed substanceswithin the sample cavity 16 and the enzyme substance within the cavity18 will simultaneously be supplied under pressure provided by thepistons 26 of the storage cavities 16 and 18 to the distributionmanifolds 52 and S4. Enzyme will be supplied under such pressure throughthe check valve 78 into the reagent injection chamber 92. Such pressureadditionally reciprocates the piston 88 in order to accommodate theincreasing volume of enzyme supplied to the injection chamber 92. Thepiston will continue to rise until the volume adjustment nut impingesagainst the injection spring retainer 104. Accordingly, the volume ofenzyme accepted by the injection chamber 92 is positively controlled byproper adjustment of the volume adjustment nut 110. Simultaneously, themixed sample and ATP extracts from the manifold 52 are supplied throughthe check valve 72 into the sample reaction chamber 100. The floatingpiston 94 will reciprocate in response to the expanding volume of sampleaccepted into the reaction chamber 100 until the adjustment screw 98stops against the piston 88. Accordingly, the volume of sample acceptedinto the reaction chamber 100 can be adjustably controlled by a propersetting of the adjustment screw 98.

At this point in the operation the valves 72 and 78 are closed therebyisolating the injection chamber 92 and the reaction chamber 100. Themotor 114 is then actuated to operatively rotate the rotary shaft 62. Bysuch operation, the groove conduit 116 is brought into registration withthe passageways 1 l8 and of the injection chamber 92 and the reactionchamber chamber 100. Simultaneously, the ball release mechanism 112 isrotated to bring the recess 113 in registration with the ball latch 106,permitting the same to be withdrawn from the groove 108 of the injectionspring retainer 104. Accordingly, the compressed coil spring 102 ispermitted to expand, thereby reciprocating the piston 88 and purging theinjection chamber 92 of the enzyme which is caused to flow through thepassageway 118, the conduit 116, the passageway 120 and into the samplereaction chamber 100. Such reciprocation of the piston 88 permits acorresponding reciprocation of the piston 94, permitting expansion ofthe reaction chamber 100 to accommodate the increase in volume thereofdue to the enzyme received therein. Additionally, rotation of the rotaryshaft 62 rotates photomultiplier (not shown) initially from a positionwithin the magnetic shield casing 122 to a position in registration withthe glass window 68 covering the reaction chamber 100. Accordingly, thephotomultiplier is operatively positioned upon rotation of the rotaryshaft 62 to monitor the mixed constituents within the reaction chamber100.

Accordingly, and in accordance with the objects of the presentinvention, the preferred embodiment of the invention is a dual pistonsample analysis instrument which both meters the amount of the reactantsand pumps the same into the reaction chamber. Additionally, the presentinvention utilizes an uncomplicated mechanism in the form of a rotaryshaft for accomplishing within significant time relationships, threefunctions: namely, releasing a ball detent latch and enzyme injectionspring, activating a conduit permitting enzyme to flow from an injectionchamber into a reaction chamber where it is mixed with a sample to beanalyzed, and supporting and positioning a photomultiplier tube from aprotected position to a position whereby monitoring of the mixedconstituents is accomplished. Other embodiments and modifications of thepresent invention are apparent and intended to be protected by the scopeof the appended claims.

It is claimed:

1. A pumping and metering system comprising:

means for storing a sample to be analyzed;

means for storing a reagent separately from said sample;

a housing defining a reaction chamber in communication with saidsample-storing means and an injection chamber in communication with saidreagent storing means;

metering means for adjustably controlling the volume of said reactionchamber and said injection chamber, said metering means including afirst piston slidable within said housing and mounted on an elongatedshaft thereby defining said injection chamber and a second slidablepiston mounted on said shaft within said housing thereby defining saidreaction chamber;

adjustment means to control the volume of said reaction chamberincluding a nut threadably adjustable on said shaft and providing a stopin order to limit sliding travel of said second piston;

initially closed valve means providing communication between saidreaction and said injection chambers; pumping means for transferringreagent from said injection chamber to said reaction chamber; and,

automatically actuable means for actuating said valve means and saidpumping means in a properly determined timed sequence.

2. The structure of claim It, wherein said automatically actuable meanscomprises a rotatable shaft and said valve means comprises a grooveconduit in said shaft.

3. The structure of claim 1, and further including a radiation shieldedhousing containing a pivotally mounted detector means, said automaticactuable means being so constructed and arranged to open said valvemeans, activate said pumping means and pivot said detector means intoregistration with said reaction chamber.

4 The structure of claim ll, wherein said pumping means includes a coilspring surrounding said shaft, a spring retainer slidably receiving saidshaft and retaining said coil spring initially in compression, latchingmeans initially precluding motion of said retainer means, saidautomatically actuable means adapted to release said latching meanspermitting expansion of said coil spring for transferring said reagent,said adjustment nut adapted for engagement on said spring retainer.

5. The structure of claim 1 and further including a first distributionmanifold providing communication between said sample-storing means andsaid reaction chamber and a second distribution manifold providingcommunication between said reagent-storing means and said injectionchamber.

6. The structure of claim 5 and further including an automaticallyactuable distribution valve operatively associated with saidsample-storing means and said reagent-storing means for simultaneouslysupplying sample and reagent to said manifolds.

2. The structure of claim 1, wherein said automatically actuable means comprises a rotatable shaft and said valve means comprises a groove conduit in said shaft.
 3. The structure of claim 1, and further including a radiation shielded housing containing a pivotally mounted detector means, said automatic actuable means being so constructed and arranged to open said valve means, activate said pumping means and pivot said detector means into registration with said reaction chamber.
 4. The structure of claim 1, wherein said pumping means includes a coil spring surrounding said shaft, a spring retainer slidably receiving said shaft and retaining said coil spring initially in compression, latching means initially precluding motion of said retainer means, said automatically actuable means adapted to release said latching means permitting expansion of said coil spring for transferring said reagent, said adjustment nut adapted for engagement on said spring retainer.
 5. The structure of claim 1 and further including a first distribution manifold providing communication between said sample-storing means and said reaction chamber and a second distribution manifold providing communication between said reagent-storing means and said injection chamber.
 6. The structure of claim 5 and further including an automatically actuable distribution valve operatively associated with said sample-storing means and said reagent-storing means for simultaneously supplying sample and reagent to said manifolds. 